Exemplary embodiments relate to a method for detecting different types of demands for workloads and to activating temporary resources for the workloads.
Today's high-end computers have a large number of processors. These processors are so powerful that adding another processor changes the capacity of this computer by a high amount. That is why, e.g., on a zSeries® machine, there is the ability to run the processor at various speed levels for general-purpose processors. With these two variables (number of processors and the processor speed) the processing capacity can be adjusted much more granularly. Table 1 below shows such configurations for a subset of a zSeries ® z9®-EC machine. Each cell in the table contains the information about the configuration identifier and the associated general-purpose capacity. General-purpose capacity is expressed in terms of million service units (MSU).
A zSeries machine may be called a central processor complex (CPC). Beginning with a configuration of nine processors, all processors are running with the maximum speed. In these computers, there are other specialty processors that can be used for other specific workloads, for example a Java workload.
TABLE 11 CP2 CP3 CP4 CP5 CP6 CP7 CP8 CP9 CPSpeed 470170270370470570670770870981158229298363422479532584Speed 3601602603604605606607608n/a65127184240292339385428Speed 2501502503504505506507508n/a53104152197240279317352Speed 1401402403404405406407408n/a285580103126147166185
It is possible to partition these large computers to run multiple operating systems and operating system instances on them. For zSeries machines, such a partition is called a logical partition (LPAR). For each LPAR, it is possible to assign physical processors to the LPAR. Such processors can be dedicated to the LPAR, which means that the partition will exclusively use the assigned processors. In contrast, an LPAR can get assigned shared processors, which means that the processors are shared with other LPARs and that the physical processors get assigned to this or another LPAR whenever the processors are needed.
Customers usually buy a permanent configuration with the general-purpose capacity and a number of specialty processors that suits their current needs. Nevertheless, there are situations when more capacity is needed, for example, when an unexpected number of requests have to be processed. To account for such a situation, these computers are allowed to temporarily activate additional capacity. This additional capacity can be provided as additional processors, higher processors speed, or a combination of additional processors and higher speed for general-purpose capacity. For specialty processors only the number of processors can be increased.
Today, customers have to buy such temporary capacity by requesting the capacity configuration that they expect will resolve such unexpected situations in business. When the need arises, the customer can activate this target configuration. To allow for this, actual computers are built and delivered with more processors than the number bought by the customer.
However, such manual activation has some drawbacks. First, it may happen that the activated capacity does not help the workload that is suffering. This can be the case if the type of additional capacity cannot be absorbed or is of an incorrect type. In this situation, the customer had to pay for the activation but still did not fulfill the business needs. Another problem could be that the activated capacity is too high for the current situation, and thus the customer has to pay for more than is necessary.
To help in this situation, newer machines allow activating additional temporary capacity, for example to any target configuration shown in Table 2 below. The allowed target configurations for a customer may be limited by a maximum capacity to activate or by a maximum number of processors. The Table 2 shows allowed targets for general-purpose capacity that is allowed in the case that a customer bought a CPC with a permanent configuration (PC) of 3 general-purpose processors (CP) running at speed level 2. This configuration has the Id 503 and it has a capacity of 152 MSUs. If the additional temporary capacity is limited to not allow for more than double the capacity of the permanent configuration, then all the configurations in Table 2 can be activated.
TABLE 23 CP4 CP5 CP6 CPSpeed 4703704229298Speed 3603604605184240292Speed 2503504505506152197240279PC
Usually, the customer would not want to activate the additional capacity just in case the machine is running near 100% utilization, which is a normal situation for mainframe computers. However, the additional capacity may need to be activated in case a business-critical workload does not fulfill its goal. This issue is addressed for particular resources, like specialty processors, in DE9-2006-0016, herein incorporated by reference.
The situation for general-purpose capacity is much more complex. The reason is that adding capacity with processors and adding capacity with higher speed does not have the same effect for all workloads. It would be beneficial to have a method for properly adding capacity.